The combination of an aging electrical grid infrastructure and integration of intermittent generation sources from large scale renewable energy resources (such as wind, solar, and ocean waves) has increased the critical need to develop effective energy storage technologies to achieve power supply stability of the grid and shift electric power supplies during peak and off-peak periods. Electricity providers are looking for ways to add clean power to the grid, prevent power outages and manage peak loads in a cost effective way without adding additional generating capacity. Storage batteries are critical elements in the expansion and large-scale adoption of renewable energy sources such as wind power and solar farms.
To date, no single battery system is commercially successful in this application. There are several reasons for this. One reason is the high cost of existing battery systems. Consequently, electricity providers prefer using gas turbines to provide peak power to the grid as needed. However, gas turbines are not as versatile or useable as true storage devices such as batteries. A second reason is that current battery cycle life is too low, making true lifetime costs much higher than the initial battery cost. Another reason is that many batteries (such as sodium-sulfur batteries) operate at elevated temperatures, contain hazardous chemicals, or may be subject to secondary detrimental chemical reactions such as those occurring in lithium based batteries. In short, there is no current commercial battery technology that offers large scale battery size, suitable performance, and long discharge/charge cycle life at a commercially viable price and a viable service life for electricity providers.
Ideally, electrochemical charging of a cell or battery is such that 60% or more, preferably 80% or more, and more preferably 90% or more of a battery or cell's prior discharge capacity can be available again for useful discharge capacity within an electrochemical charging period of one hour or less, and preferably within 30 minutes or less.
Therefore, a need exists for improved battery systems. A further need exists for rechargeable battery configurations that are commercially viable.